Thread: Dust Extraction System - Powermatic 1792072K

I think you are overly optimistic to think you can do all this is one day - I would allocate a week at least to do it properly.

It will be a real shame to set up 200mm then 150 and then drop it down to 100 mm at each machine as the 100mm ducting and ports are a complete DOG as it will never let more than 400 CFM though the duct no matter what the size is of the rest of the ducting. This means MUCH LESS air and dust are collected at source and that uncollected dust will continue to flood your shed.
To get effective dust extraction the 100mm dust ports on machines have to be opened up to 150 mm , or you need 3 x 100 mm ducts to each machine to collect the same amount of air and dust.
Worse still, because the 4" can only deliver 400 cfm that is also all that will be flowing through the 200 mm (8") ducting . 400 cfm through an 8" pipe equals only about 1200 FPM air speed which means the sawdust will settle out and restrict the flow of ai in the 8" pipe. The same applied to the 4" to 6" ducting transition.

It is really easy to make a 150 mm machine port.
These 150 mm flanges are not that expensive.

150mmflange.jpg

Cut out a 200 x 200 piece of stuff (MDF or ally or sheet metal etc) and cut a 150 mm hole in the middle and Tek-screw/rivet/bolt and glue a flange over the hole.
Cut a 150 x 150 mm hole in the machine cabinet and attach and seal the 200 x 200 stuff over the top of the hole.


A few points

1. Instead of hard 90º bends near the start of your system, for each 90º use 2 x 45º separated by a short length of ducting
2. The blast gates should be just after the branch and not at the machine.
3. If you insist on using 4' Ducting and ports then you can still keep the 150 and 200 mm system by opening up all the dust ports at the end of every dust making session to help clear the dust ithat has settled in those pipes. I would recommend doing this every now and then during a session as well as this will help clear the dust out of the shed.
4. I note that your DC is inside your shed - this is self defeating as they ALL leak so you will fill your shed up with fine dust anyway. THE MOST IMPORTANT THING you can do for controlling dust is get the DC outside or put it in a sealed enclosure and vent it outside the shed

There's more but lets get you to digest that lot first

Cheers Bob,

Thank you for the tips re. increasing my ports. Where could I buy those flanges?

So as I thought, if I was to begin at the extractor end (200mm) and create a trunk moving up to the ceiling and then carried that up the length of my work space (5metres) that would be my best bet to begin with? If so where could I get the required pipe online? I know that PVC is only available in 225mm and I have tried working with a piece of that to no avail.. too big! Also it is really heavy and I am not sure how much weight my shed can handle!!

Also I would need to then break off into 6 150mm branches (PVC) where I would place the blast gates, so the 200mm trunk would need to accommodate these branches.

I would then run these branches direct to the machines where possible.

Now.. where do I get the components? 200mm PVC or cheap alternative seems elusive in my searching!

Yes, I would love to have the DE outside but unfortunately this is not an option in the near future. I am wearing a dust mask most of the time just to be safe.

Also, 150mm blast gates..

Do I have to make them or does someone know where they are available online, hopefully that fit PVC down pipe..

Originally Posted by Miko Zaire

Cheers Bob,

Thank you for the tips re. increasing my ports. Where could I buy those flanges?

You will have to get those flanges from a plumbing specialist.

Unless you plan to use more than one machine at a time I wouldn't bother with any 8' - just use 6"

Blast gates are available from ClearVue (http://clearvueoz.com.au/accessories/) not cheap but nothing 6" is cheap.

I really feel sorry for folks who have to wear masks all the time in their shed.
If you cannot get your DC outside can you at least enclose it and vent it outside?
This would be my number one priority - its far more important to do this than anything else you plan to do.

I agree with BobL on this. To use 4" duct on that DE is just a complete waste of its capacity, and the money you spent on it. Isn't there any possibility of building a little lean to outside the shed to house the DE? Makes more room in the shed too, double win!

I would expect at least a couple of days and that's with everything going well to hook all the machines up.

150mm plastic is your best option, fittings are available for most of what you want to do, the exception might be the 200 to 150 transition at the DE, this transition is called a truncated cone, google it for plans and how to make if you want to go this way, in previous posts Bob has said make these types of transition lengths about 5D, (5 times the diameter) any time you change pipe size, make a machine hood or pickup point, add in a fitting, or any sort of pipework you should always aim for a smooth change, any sort of abrupt change is detrimental to airflow, square edges for e.g., the next best option is to use one of those flanges that Bob previously posted, at least this gives you a radius at the inlet to the DE, not sure on sizes but you may have to make an adaptor ring, mdf or such, put a radius on this as well.


Pete

Thanks guys!

Yeh at the moment the problem is space outside of the shed, something I could arrange but not until my next break (December/Jan) so for now I will have to keep it inside. I am with you fellas. I would love it out side.


So Bob, how would I vent my particular DE outside? I could easily knock up a little box for it.


Also, Bob should I just look to run the 200mm into 2x150mm pipes direct from the DE and then to both sides of my shop?

Cheers

Originally Posted by Miko Zaire

So Bob, how would I vent my particular DE outside? I could easily knock up a little box for it.

The whole DC needs to be in a well sealed cupboard (remember it will be under positive pressure relative to the shed which under negative pressure) so you don't want air/dust leaking back into the shed.
And ideally the vent/exit to the exterior of the shed should be 4 x the area of the largest ducting used in a system.

Also, Bob should I just look to run the 200mm into 2x150mm pipes direct from the DE and then to both sides of my shop?

Cheers

Unless you plan to run more than one machine simultaneously then 8" is a waste of money.

Yep, I will only operate one machine at a time so ill stick with the 150mm throughout the shop. I unfortunately do not have another spare 2 day weekend until the end of August so I will get onto my planning and ordering so it is ready to install then.

I had a look last night at my machines and I rekon I have a chance of expanding the holes or re-cutting holes for most machines which I will post when I get to it later in the year. Although.. I am unsure about the PM2000 as it is quite an unusual type of system internally - inside the cab the 100mm dust output is fed directly into a 2.5" or 3" pipe which connects to a funnel under the saw, the cabinet is half full of chips.. Sould I just cut another separate hole for a 150mm above it?

So I think now I only need to to buy or make something to take my 200mm inlet from DE to a double 150mm


You guys are a great help thanks!

Originally Posted by Miko Zaire

Yep, I will only operate one machine at a time so ill stick with the 150mm throughout the shop. I unfortunately do not have another spare 2 day weekend until the end of August so I will get onto my planning and ordering so it is ready to install then.

I had a look last night at my machines and I rekon I have a chance of expanding the holes or re-cutting holes for most machines which I will post when I get to it later in the year. Although.. I am unsure about the PM2000 as it is quite an unusual type of system internally - inside the cab the 100mm dust output is fed directly into a 2.5" or 3" pipe which connects to a funnel under the saw, the cabinet is half full of chips.. Sould I just cut another separate hole for a 150mm above it?

While I can recommend from afar increasing the size of machine ports its a bit harder to recommend what to do for the inside of a machine. The best thing to do would be some major surgery and strip out everything that gets in the way so that 6" ducting could be located under the saw blades.

dust extracting from a TS is usually a major project on its own. Most saw blade guards are rubbish at dust collection because the use ducting that is too small and the guards also need to be rebuilt to accommodate at least 4"ducting. With 6" extraction on the cabinet and 4" on the guard this will improve the dust collection considerably.

So I think now I only need to to buy or make something to take my 200mm inlet from DE to a double 150mm

That's not the best way to do it as it will create too much turbulence close to the impeller and restrict air flow
The best way is to make/use an 8" to a single 6" adapter and come away from the 8" inlet using just one 6" pipe, then some way further along branch using a Y to two 6" ducts (NB you will need 2 last gates at that point)

BTW I made an 8" to 6" adapter out of a longish plastic pot plant.
see https://www.woodworkforums.com/f200/bobls-dusty-setup-143350

So I think now I only need to to buy or make something to take my 200mm inlet from DE to a double 150mm


That's not the best way to do it as it will create too much turbulence close to the impeller and restrict air flow
The best way is to make/use an 8" to a single 6" adapter and come away from the 8" inlet using just one 6" pipe, then some way further along branch using a Y to two 6" ducts (NB you will need 2 last gates at that point)

BTW I made an 8" to 6" adapter out of a longish plastic pot plant.
see https://www.woodworkforums.com/f200/bobls-dusty-setup-143350


Bob you are a bloody legend! Ill get on to it! I will try to find some time to re-draw up my original design to reflect the changes you advised! Thanks

Originally Posted by Miko Zaire

I had a look last night at my machines and I rekon I have a chance of expanding the holes or re-cutting holes for most machines which I will post when I get to it later in the year. Although.. I am unsure about the PM2000 as it is quite an unusual type of system internally - inside the cab the 100mm dust output is fed directly into a 2.5" or 3" pipe which connects to a funnel under the saw, the cabinet is half full of chips.. Sould I just cut another separate hole for a 150mm above it?

Can you do a few pics of inside the cabinet?


Pete

Can you do a few pics of inside the cabinet?

When I get home next week Pete I will take a few pictures.